Error when joining A4 pages in mode "first columns, then rows"

[lucielavickova]

When trying to join A4 pages and selecting the option "first columns, then rows", I get an error "ValueError: max() arg is an empty sequence" when I change to "first rows, then columns", this error does not occur.

Sewing pattern: https://cdn.shopify.com/s/files/1/0606/4737/5098/files/Made_for_Motti_-_Hose_Motti.pdf?v=1634755509

[cfcurtis]

This is an interesting one, with 19 pages and 6 columns, PDFStitcher calculates that 4 rows are required (rounding up 19 / 6). However, if you fill the columns first, then you get an empty column at the end, which is where the empty sequence came from:

Rows first:

1	2	3	4	5	6
1	2	3	4	5	6
7	8	9	10	11	12
13	14	15	16	17	18
19

Columns first:

1	2	3	4	5	6
1	5	9	13	17
2	6	10	14	18
3	7	11	15	19
4	8	12	16

What behaviour would you expect in this situation? The options that I can think of are either:

1. Notify the user that the selected arrangement does not work
2. Drop down to 5 columns (and also probably notify the user)

[lucielavickova]

aaaah, by bad, I confused rows and columns when selecting the 6.... In that case, my preferred option would be the first suggested solution - notify, that the arrangement does not work. Thank you very much!